THE EXPERIENCE OF DRIVERS AND THE PERFORMANCE OF DRIVING AS IMPACT FACTORS OF VIBRATION LEVELS IN AGRICULTURAL TRACTORS

Abstract

During everyday operations with tractors, drivers are exposed to harmful effects of various factors. One of the negative factors are vibrations deriving from driving aggregates and implements combined with the rough soil. These oscillatory loads are transferred to the cab, and through the floor and the seat to the body of the driver. In case of high level vibrations and during a long period of exposure to them, many health problems occur. Harmful effect of the vibrations is especially obvious in older models of tractors which don't have proper suspension, but are equipped with simple mechanical seats.. During measuring of vibrations at the seat of the driver, high intensities of vibrations were found, above permitted limits. A quality seat and suspension as well as good tires affect both the intensities of vibrations and their reduction. Organizational measures such as shorter working shifts and a change of drivers can only reduce the level of daily exposure, but can’t affect neither the intensity of vibrations nor their reduction. On the other hand, the drivers’ awareness of vibrations’ harmful effect, detailed trainings and drivers’ experience can affect the vibration level significantly. This work presents an attempt to show the effect of drivers’ experience on the intensities of vibrations. A skillful driver, i.e. the performance of his driving, can have considerable influence on vibration level, with the effect more obvious in older tractor models than in new ones. The measurement results, with three different drivers (in the same working conditions: the same tractor model, type of soil and working operation), show how influential for the vibration level the driver’s skills i.e. well-performed driving are. A skillful driver, in almost same working conditions, can reduce vibration levels even 20 times in comparison to an inexperienced one